Plastic compositions

ABSTRACT

Plastic compositions containing elastomers and bis-phenoxy compounds having the formula   &lt;IMAGE&gt;   WHEREIN Z is bromine, m is an integer having a value of 1-5 and m&#39; is an integer having a value of 0-4, i is an integer having a value of 0-2 and i&#39; is an integer having a value of 1-5, alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms and A is chlorine.

The prior art considered in conjunction with the preparation of thisapplication is as follows: U.S. Pat. Nos. 2,130,990; 2,186,367;2,329,033; 3,666,692; 3,686,320; 3,658,634; German Pat. No. 1,139,636;German Pat. No. 2,054,522; Japanese Pat. No. (72) 14,500 as cited inVolume 77, Chemical Abstracts, column 153737k (1972); ChemicalAbstracts, Volume 13, column 448⁵ ; Chemical Abstracts, Volume 31,column 7045⁹ ; and Journal of the Chemical Society, pages 2972-2976(1963). All of these publications are to be considered as incorporatedherein by reference.

The present invention relates to plastic compositions containingelastomers. More specifically, the present invention covers plasticcompositions containing elastomers and certain bis-phenoxy compounds(hereinafter defined) as flame retardants for said plastic compositions.

Elastomers and utility thereof are known in the art as exemplified byTextbook of Polymer Science, F. W. Billmeyer, Jr., Second Edition, pages533-550, John Wiley & Sons, Inc., New York, 1971 and Encyclopedia ofChemical Technology, Kirk-Othmer, Second Edition, Vol. 7, pages 676-716,John Wiley & Sons, Inc., New York, 1965 and which publication are intoto incorporated herein by reference.

The need for flame retarding elastmers has also been recognized in theart as exemplified by the two above-described publications and ModernPlastics Encyclopedia 1972-1973, Vol. 49: 10A, October, 1972, pages456-458 and which publication is in toto incorporated herein byreference.

The resultant disadvantages in the utilization of various prior artmaterials as flame retardants for elastomers include, withoutlimitation, factors such as thermal migration, heat instability, lightinstability, non-biodegradable, toxicity, discoloration and the largeamounts employed in order to be effective. Thus, there is always ademand for a material which will function as a flame retardant inelastomers and concurrently will not, by incorporation therein,adversely effect the chemical and/or physical and/or mechanicalproperties of the resultant elastomer plastic composition.

The prior art problem of providing a flame retarded elastomercomposition having desired chemical, physical and mechanical propertieshas now been substantially solved by the present invention and theabove-described disadvantages substantially overcome.

Accordingly, one of the main objects of the present invention is toprovide elastomer plastic compositions which are flame retarded.

Another object of the present invention is to provide a material forelastomer plastic compositions which not substantially adversely effectthe chemical and/or physical and/or mechanical properties of saidcompositions.

A further object of the present invention is to provide a flameretardant which is economic and easy to incorporate into elastomerplastics without being degraded or decomposed as a result of blending orprocessing operations.

It has been found that the foregoing objects can be obtained by theincorporation of a new class of bis-phenoxy compounds in elastomers tosubsequently provide flame retarded compositions which exhibitoutstanding chemical, physical and mechanical properties.

The bis-phenoxy compounds used in the present invention compositionshave the formula: ##STR2##

In Formula I above, Z is bromine; m is a integer having a value of 1-5and m' is an integer having a value of 0-4; i is an integer having avalue of 0-2 and i' is an integer having a value of 1-5; alkylene is astraight or branched chain alkylene group having from 1 to 6 carbonatoms (e.g. CH₂, C₂ H₄, C₃ H₆, C₄ H₈, C₅ H₁₀, C₆ H₁₂ and CH₂ CH(CH₃)CH₂; and A is chlorine.

It is to be understood that all of the compounds falling within theabove Formula I and as heretofore defined are generically describedherein as "bis-phenoxy" compounds.

The bis-phenoxy compounds are found to be compatible with and effectiveadditives for various polymeric systems to make the resultant polymerfire retardant.

Illustrative (but without limitation) of some of the present inventionbis-phenoxy compounds are shown below: ##STR3## the exemplarydefinitions of A, Z, i, i', m, m' and alkylene are listed in Table I.

                  Table I                                                         ______________________________________                                        Compound                                                                      No.     Z      m      m'  A   i   i'  Alkylene                                ______________________________________                                         1      Br     2      2   Cl  1   1   CH.sub.2                                 2      Br     2      2   Cl  1   1   C.sub.2 H.sub.4                          3      Br     2      2   Cl  1   1   C.sub.3 H.sub.6                          4      Br     3      0   Cl  0   5   C.sub.2 H.sub.4                          5      Br     3      0   Cl  0   5   C.sub.3 H.sub.6                          6      Br     3      0   Cl  0   5   C.sub.4 H.sub.8                          7      Br     3      3   Cl  1   1   C.sub.4 H.sub.8                          8      Br     2      2   Cl  2   2   C.sub.3 H.sub.6                          9      Br     2      2   Cl  2   2   C.sub.4 H.sub.8                         10      Br     5      0   Cl  0   5   C.sub.2 H.sub.4                         11      Br     5      0   Cl  0   5   C.sub.4 H.sub.8                         12      Br     2      2   Cl  1   1   C.sub.6 H.sub.12                        13      Br     3      0   Cl  0   5   C.sub.6 H.sub.12                        14      Br     4      1   Cl  1   4   C.sub.2 H.sub.4                         15      Br     3      3   Cl  1   1   C.sub.3 H.sub.6                         16      Br     3      3   Cl  1   1   C.sub.6 H.sub.12                        17      Br     2      2   Cl  2   2   C.sub.2 H.sub.4                         18      Br     4      4   Cl  1   1   C.sub.3 H.sub.6                         19      Br     3      3   Cl  1   1   C.sub.2 H.sub.4                         20      Br     3      3   Cl  2   2   C.sub.3 H.sub.6                         21      Br     2      2   Cl  1   1   CH(CH.sub.3)CH.sub.2                    22      Br     4      4   Cl  1   1   CH(CH.sub.3)CH.sub.2 CH.sub.2           23      Br     3      3   Cl  2   2   CH.sub.2 CH(CH.sub.3)CH.sub.2 CH        24      Br     1      1   Cl  1   1   CH.sub.2                                25      Br     1      1   Cl  1   1   C.sub.2 H.sub.4                         ______________________________________                                    

In general, the bis-phenoxy compounds are prepared by reacting ahalogenated phenol with a halogenated alkane at elevated temperatures inthe presence of a basic material such as alkali metal hydroxides,carbonates, bicarbonates, oxides and hydrides. The preferred alkalimetals are potassium and sodium. Where one desires to increase, forexample, ease of handling the reaction mass, solvents such as ketones(e.g. acetone, methyl ethyl ketone, and methyl iso-butyl ketone),alcohols (e.g. methanol, ethanol, iso-propyl alcohol, butyl alcohol andglycols), or aqueous solvents (e.g. water, a mixture of water andalcohol and a mixture of water and ketone) can be employed. The desiredend product, i.e. the bis-phenoxy compound, can be recovered from thereaction mass via various methods such as distillation orcrystallization. Where the end product requires recovery viacrystallization, various aromatic solvents such as benzene, toluene,xylene, dichlorobenzene and the like can be used.

Specifically, the bis-phenoxy compounds are prepared according to thefollowing reactions: ##STR4##

In the above reaction, X is halogen, preferably chlorine and alkylene isthe same as herein defined. Where m and m' and i and i' are differentintegers, then equivalent molar portions of the particular halogenatedphenol are used with equivalent portions of dissimilar halogenatedphenol.

The above reaction is conducted at temperatures ranging from thefreezing point of the initial reaction mass to the boiling pointthereof. Preferably the temperatures are from about 40° to about 200° C.and more preferably from about 50° to about 175° C. It is to beunderstood that the reaction can be conducted under sub-atmospheric(e.g. 1/10-8/10 atmospheres), atmospheric or super-atmospheric (e.g.1.5-10 atmospheres) pressure. Preferably, the reaction is carried out atatmospheric pressure.

The above-described processes can be carried out with conventional,readily available chemical processing equipment. For example, aconventional glass-lined vessel provided with heat transfer means, areflux condenser and a mechanical stirrer can be advantageously utilizedin practicing any of the preferred embodiments of the inventiondescribed in the examples set forth herein.

The amount of bis-phenoxy compound employed in the present inventioncompositions is any quantity which will effectively render the elastomercontaining composition flame retardant. In general, the amount used isfrom about 1% to 25% by weight, based on the total weight of thecomposition. Preferably, the amount employed is from about 5% to about20% by weight. It is to be understood that any amount can be used aslong as it does not substantially adversely effect the chemical and/orphysical and/or mechanical properties of the end polymer composition.The amount utilized, however, is such amount which achieves theobjectives described herein.

It is to be understood that the term elastomers as used herein means amaterial which at room temperature stretches under low stress to atleast twice its length and snaps back to the original length uponrelease of stress. This includes, without limitation, materials such asnatural rubber, butadiene polymers, 2-chlorobutadiene polymers, isoprenepolymers, silicone rubber, chlorosulfonated polyethylene, andpolyethers.

Thus the elastomers used in the present invention compositions is anyelastomers herein defined and which one so desires to flame retard. Itis to be understood that the elastomers used can be a "virgin" material,i.e. substantially free of additives such as stabilizers, plasticizers,dyes, pigments, fillers, and the like, or the elastomers can haveadditives (such as those mentioned and described herein) alreadycontained therein or added concurrently with or after the addition ofthe bis-phenoxy compounds.

Another facet of the present invention relates to the use of certainmetal compounds with the bis-phenoxy compounds to promote a cooperativeeffect therebetween and thus enhance the flame retardancy of theresultant plastic composition as compared to the flame retardancy ofeither one component used separately. These "enhancing agents" are fromthe group antimony, arsenic, bismuth, tin and zinc-containing compounds.Without limitation, examples of said enhancing agents include Sb₂ O₃,SbCl₃, SbBr₃, SbI₃, SbOCl, As₂ O₃, As₂ O₅, ZnBO₄, BaB₂ O₄.sup.. H₂ O,2.sup.. ZnO.sup.. 3B₂ O₃.sup.. 3.5H₂ O and stannous oxide hydrate. Thepreferred enhancing agent is antimony trioxide.

The amount of enhancing agent employed in the present inventioncompositions is any amount which when used with said bis-phenoxycompounds will promote a cooperative effect therebetween. In general,the amount employed is from about 1% to about 15%, preferably from about2% to about 10%, by weight, based on the total weight of plasticcomposition. Higher amounts can be used as long as the desired endresult is achieved.

It is also within the scope of the present invention to employ othermaterials in the present invention compositions where one so desires toachieve a particular end result. Such materials include, withoutlimitation, adhesion promotors; antioxidants; antistatic agents;antimicrobials; colorants; flame retardants such as those listed onpages 456-458, Modern Plastics Encyclopedia, ibid, (in addition to thenew class of flame retardants described herein); heat stabilizers; lightstabilizers; pigments; plasticizers; preservatives; ultravioletstabilizers and fillers.

In this latter category, i.e. fillers, there can be mentioned withoutlimitation, materials such as glass; carbon; cellulosic fillers (woodflour, cork and shell flour); calcium carbonate (chalk, limestone, andprecipitated calcium carbonate); metal flakes; metallic oxides(aluminum, beryllium oxide and magnesia); metallic powders (aluminum,bronze, lead, stainless steel and zinc); polymers (comminuted polymersand elastomer-plastic blends); silica products (diatomaceous earth,novaculite, quartz, sand, tripoli, fumed colloidal silica, silicaaerogel, wet process silica); silicates (asbestos, kaolimite, mica,nepheline syenite, talc, wollastonite, aluminum silicate and calciumsilicate); and inorganic compounds such as barium ferrite, bariumsulfate, molybdenum disulfide and silicon carbide.

The above mentioned materials, including fillers, are more fullydescribed in Modern Plastics Encyclopedia, ibid, and which publicationis incorporated herein (in toto) by reference.

The amount of above described materials employed in the presentinvention compositions can be any quantity which will not substantiallyadversely effect the desired results derived from the present inventioncompositions. Thus, the amount used can be zero (0) percent, based onthe total weight of the composition, up to that percent at which thecomposition can still be classified as a plastic. In general, suchamount will be from about 0% to about 75% and specifically from about 1%to about 50%.

The bis-phenoxy compounds can be incorporated in to the elastomers atany processing stage in order to prepare the present inventioncompositions. In general, this is undertaken prior to fabrication eitherby physical blending or during the process of forming elastomers per se.Where one so desires, the bis-phenoxy compounds may be micronized intofinely divided particles prior to incorporation into the elastomers.

EXAMPLE I

An elastomer plastic material, a compounded ethylene propylene dienemonomer (EPDM) rubber (prepared by mixing together 100 parts Uniroyal'sRoyalene 512-EPDM rubber, 50 parts carbon black, 15 parts naphthenicoil, 5 parts zinc oxide, 1 part stearic acid, 0.5 parts2-mercaptobenzothiazole, 1.5 parts tetramethylthiuram monosulfide and1.5 parts sulfur) is utilized as the base resin in order to prepare 26formulations (plastic compositions). With the exception of formulationNo. 1, the particular bis-phenoxy compound (and the antimony trioxideenhancing agent where indicated) is incorporated into the plastic byadding both to a Brabender mixer ("Plastic-Corder", Torque Rheometer,Model PLV-150, C. W. Brabender Instruments Inc., South Hackensack,N.J.). The mixer is equipped with a pair of roller type bladespositioned within a head provided with heat transfer means.

The resultant mixture is heated to about 320° C.; at this temperature,it is in a molten state. The percentages by weight of each componentutilized in the respective formulations are listed in Table II. Eachformulation is discharged from the mixer and upon cooling solidifies andis ground into chips. The chips are subjected to compression molding ina Wabash press by placing said chips between two platens, the bottom ofwhich contains four equal size depressions 3 inches by 5 inches by 1/8inch deep. The top platen is then placed over the bottom platen and heattransfer means supplied thereto in order to melt said chips and thusprovide solid samples (after cooling) for testing.

Portions of the samples of each respective formulation (Nos. 1-26)prepared according to the above described procedure are then subjectedto two different standard flammability tests, i.e. UL 94 and ASTMD-2863-70. The UL 94 is, in general, the application of a burner to atest specimen (strip) for a certain period of time and observation ofcombustion, burning, and extinguishment. This procedure is fully setforth in Underwriters' Laboratories bulletin entitled UL 94, Standardfor Safety, First Edition, September 1972 and which is incorporatedherein by reference. ASTM No. D-2863-70 is a flammability test whichcorrelates the flammability of a plastic specimen to the availableoxygen in its immediate environment; this correlation is stated as anOxygen Index, O.I., level predicated upon the percent oxygen in thegaseous medium which is required to just provide a steady state ofcontinuous burning of the plastic specimen. This ASTM method is fullydescribed in 1971 Annual Book of ASTM Standards -- Part 27, published bythe American Society For Testing and Materials, 1916 Race Street,Philadelphia, Pa.; this publication is to be considered as incorporated(in toto) herein by reference.

The results of these flammability tests are shown in Table II.

                  TABLE II                                                        ______________________________________                                        FLAMMABILITY DATA FOR ELASTOMER                                               PLASTIC COMPOSITIONS CONTAINING                                               BIS-PHENOXY COMPOUNDS                                                                 BIS-              ENHANC-                                             FORMU-  PHEN-    COM-     ING     OXYGEN                                      LATION  OXY      POUND    AGENT   INDEX   UL                                  NO.     NO.      %        Sb.sub.2 O.sub.3, %                                                                   %       94                                  ______________________________________                                        1.      --        0       0       20.5    SB                                  2.       5       15       0       23.5    SE-2                                3.       5       15       5       29.5    SE-0                                4.       7       15       0       24.0    SE-2                                5.       7       15       5       33.0    SE-0                                6.       9       15       0       24.0    SE-2                                7.       9       15       5       28.5    SE-1                                8.      10       15       0       24.5    SE-2                                9.      10       15       5       30.0    SE-0                                10.     14       15       0       24.5    SE-2                                11.     14       15       5       30.5    SE-0                                12.     15       15       0       25.5    SE-2                                13.     15       15       5       31.0    SE-0                                14.     17       15       0       24.5    SE-2                                15.     17       15       5       32.5    SE-0                                16.     18       15       0       24.5    SE-2                                17.     18       15       5       35.0    SE-0                                18.     19       15       0       22.0    SE-2                                19.     19       15       5       28.5    SB-1                                20.     21       15       0       23.0    SE-2                                21.     21       15       5       31.0    SE-0                                22.     23       15       0       24.5    SE-2                                23.     23       15       5       33.5    SE-0                                24.      1       15       0       22.5    SE-2                                25.      1       15       5       27.0    SE-2                                26.      3       15       5       27.5    SE-2                                ______________________________________                                    

Referring to Table II, the bis-phenoxy compound number relates to thestructural formulae heretofor set forth in Table I; a difference of 2%in the Oxygen Index values is considered significant; and the UL 94values are on a graduated scale wherein the highest degree to lowestdegree of flame retardancy is respectively SE-0, SE-1, SE-2, SB andBurns.

The results shown in Table II demonstrate the unique effectiveness ofthese bis-phenoxy compounds as flame retardants for elastomers.Specifically, formulation No. 1 (the control) had a O.I. of 20.5 and UL94 value of SB. In Nos. 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24,the use of the particular bisphenoxy compound results in a significantincrease (1.5-5.0%) in fire retardancy as measured by O.I. (While theseformulations had a SE-2 rating, UL 94, the individual U.L. rating has awide range of values and thus the O.I. number is, in this case, moreindicative of increased flame retardancy).

The use of an enhancing agent such as Sb₂ O₃ to promote a cooperativeeffect between such agent and the bis-phenoxy compound is fullydemonstrated via the results obtained from testing formulation Nos. 3,5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25 and 26. The highest UL 94ratings and significantly higher O.I. values (7.0-14.5% increase) areobtained.

EXAMPLE II

Example I is repeated twice; once using a 10% bis-phenoxy compound leveland 3% Sb₂ O₃ level and secondly, 20% and 10% levels respectively. Atboth levels, the O.I. values and UL 94 ratings are basically the same asthe 15%/5% level of Example I.

EXAMPLE III

Portions of the solid samples of Formulation Nos. 1-26 preparedaccording to the above described procedure of Example I are subjected tothe following ASTM tests in order to ascertain other properties of theresultant plastic composition:

    ______________________________________                                        (1)  Tensile Strength                                                              (at break)     ASTM Test No. D638-61T; and                               (2)  Flexural Modulus                                                                             ASTM Test No. D790-63.                                    ______________________________________                                    

Each of the aforementioned ASTM Tests are standard tests in the art andare utilized collectively in order to ascertain the efficacy of apolymeric system as an overall flame retarded composition for commercialapplication. All of these ASTM Tests are to be considered asincorporated herein by reference.

The results of these ASTM tests show that the physical properties of thepresent invention compositions are basically the same (except O.I. andUL 94 values) as the plastic material without the flame retardant (i.e.formulation No. 1). Thus, there is no substantial adverse effect on thephysical properties of the plastic material when the novel compounds areincorporated therein.

EXAMPLE IV

The procedure of Examples I, II and III are repeated except that theenhancing agent used is zinc borate instead of Sb₂ O₃. Substantially thesame results are obtained using zinc borate as those obtained using Sb₂O₃. The other metal containing compounds are found to be equallyeffective.

EXAMPLE V

Samples of each of Formulation Nos. 1 through 26 Table II are subjectedto temperature (thermal) stability tests via the use of thermalgravimetric analysis (TGA). This test employed the use of a "ThermalBalance", model TGS-1, Perkin-Elmer Corporation, Norwalk, Conn. and anelectrical balance, Cahn 2580 model, Cahn Instrument Company, Paramount,California. The results of these tests show that the bis-phenoxycompound containing Formulations had more than adequate stability formelt processing and subsequent heat aging (i.e. high temperatureapplications) and thus demonstrating that the particular bis-phenoxycompounds are quite compatible with the plastic material. Thebis-phenoxy compound stability thus aids in providing sufficient flameretardancy at the plastic decomposition temperature. This test alsodemonstrates that these compounds do not exhibit migration.

In view of the foregoing Examples and remarks, it is seen that theplastic compositions, which incorporate these compounds, possesscharacteristics which have been unobtainable in the prior art. Thus, theuse of these compounds in the above described plastic material as flameretardants therefor is quite unique since it is not possible to predictthe effectiveness and functionality of any particular material in anypolymer system until it is actively undergone incorporation therein andthe resultant plastic composition tested according to various ASTMStandards. Furthermore, it is necessary, in order to have commercialutility, that the resultant flame retarded plastic composition possesscharacteristics such as being non-toxic. Use of these compounds in theplastic material has accomplished all of these objectives.

The above examples have been described in the foregoing specificationfor the purpose of illustration and not limitation. Many othermodifications and ramifications will naturally suggest themselves tothose skilled in the art based on this disclosure. These are intended tobe comprehended as within the scope of this invention.

What is claimed is:
 1. A plastic composition comprising elastomers and aflame retardant, said flame retardant consisting of a compound havingthe formula ##STR5## wherein Z is bromine; m is an integer having avalue of 1-5 and m' is an integer having a value of 0-4; i is an integerhaving a value of 0-2 and i' is an integer having a value of 1-5;alkylene is a straight or branched chain alkylene group having from 1 to6 carbon atoms; and A is chlorine.
 2. The composition as set forth inclaim 1 wherein i is 0 and m' is
 0. 3. The composition as set forth inclaim 1 wherein i and i' are both
 1. 4. The composition as set forth inclaim 1 wherein alkylene is CH₂.
 5. The composition as set forth inclaim 1 wherein alkylene is C₂ H₄.
 6. The composition as set forth inclaim 1 wherein alkylene is C₃ H₆.
 7. The composition as set forth inclaim 1 wherein alkylene is C₄ H₈.
 8. The composition as set forth inclaim 5 wherein m and m' are both 2 and i and i' are both
 1. 9. Thecomposition as set forth in claim 6 wherein m and m' are both 2 and iand i' are both
 1. 10. The composition as set forth in claim 7 wherein mand m' are both 2 and i and i' are both
 1. 11. The composition as setforth in claim 4 wherein m is 3, i is 0, m' is 0 and i' is
 5. 12. Thecomposition as set forth in claim 5 wherein m is 3, i is 0, m' is 0 andi' is
 5. 13. The composition as set forth in claim 6 wherein m is 3, iis 0, m' is 0 and i' is
 5. 14. The composition as set forth in claim 7wherein m is 3, i is 0, m' is 0 and i' is
 5. 15. The composition as setforth in claim 1 wherein said composition contains an enhancing agentwhich is an antimony, arsenic, bismuth, tin or zinc-containing compound.